Studies of hydrocarbons in the waters and snow-ice cover of the southeast sector of the antarctic

Data are presented on the content of hydrocarbons (HC) relative to the concentrations of particulate matter, lipids, C_org, and chlorophyll a in the surface waters and snow-ice cover of the East Antarctic coastal areas. It was shown that the growth of the concentrations of aliphatic HC (AHC) to 30 μg/l in the surface waters takes place in the frontal zones and under the young ice formation. The AHC content in the snow increases with the growth of the aerosol content in the atmosphere. In the lower part of the ice at the boundary with the seawater, despite the low temperatures, the autochthonous processes may provide high AHC concentrations (up to 289 μg/l). Within the snow-ice cover on fast ice, synchronous content variations of all the compounds considered take place.     

北太平洋和北冰洋大气中多氯联苯的浓度与气固分配行为

Polychlorinated biphenyls(PCBs) were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteristics of PCBs and their gas/particle partitioning. The mean concentration of 26 ∑PCBs(vapor plus particulate phase)(∑PCBs) was 19.116 pg/m3 with a standard deviation of 13.833 pg/m3. Three most abundant congeners were CB-28,-52 and-77, accounting for 43.0% to ∑PCBs. The predominance of vapor PCBs(79.0% to ∑PCBs) in the atmosphere was observed. PCBs were negative correlated with the latitudes and inverse of the absolute temperature(1/T). The significant correlation for most congeners was also observed between the logarithm of gas/particle partition coefficient(log KP) and 1/T. Shallower slopes(from-0.15 to-0.46, average-0.27) were measured from the regression of the logarithm of sub-cooled liquid vapor pressures(logpo L) and log KP for all samples. The difference of the slopes and intercepts among samples was insignificant(p0.1), implying adsorption and/or absorption processes and the aerosol composition did not differ significantly among different samples. By comparing three models, the J-P adsorption model, the octanol/air partition coefficient(KOA) based model and the soot-air model, the gas/particle partitioning of PCBs in the Arctic atmosphere was simulated more precisely by the soot-air model, and the adsorption onto elemental carbon is more sensitive than the absorption into organic matters of aerosols, especially for lowchlorinated PCB congeners.     

南、北极近岸海水中好氧不产氧光合基因pufM的多样性

好氧不产氧光合(AAP)细菌因其具有利用溶解性有机物及光能的能力,在海洋碳循环及能量流动中发挥着重要的作用。该类细菌广泛分布在海洋环境中,其在不同生境中的多样性已被调查。但到目前为止,人们对于高纬度地区好氧不产氧光合细菌的认识还较为缺乏。有鉴于此,本研究基于编码光反应复合物上一个色素结合蛋白亚基的pufM基因,对北极王湾及南极乔治王岛近岸水体中夏季好氧不产氧光合细菌的多样性进行了检测。针对2个王湾站位和2个南极麦克斯维尔湾站位构建了4个pufM基因克隆文库,获得674个阳性克隆子。北极克隆子全部由α-变形细菌组成,而南极克隆子则包括α-变形细菌及β-变形细菌。来源于类似红细菌科的pufM基因在所有样品中皆占据优势。此外,与一株滴状亚硫酸盐杆菌中质粒编码的pufM基因存在亲缘关系的序列,在南、北极样品中均占优势。结果表明海洋环境中的pufM基因存在跨极甚至是环球分布。与此同时,南、北极序列之间的差异,也表明了极地地方种的存在。这些结果显示,作为好氧不产氧光合细菌的红细菌科在两极的近岸水体中具有重要的地位。     

Comparison of airsea fluxes of CO2 in the Southern Ocean and the western Arctic Ocean

The data were collected during Chinese Arctic and Antarctic Expeditions in the western Arctic Ocean and the marginal sea ice zone (MSIZ) of the Southern Ocean, respectively in the boreal summer from July to September of 1999 and in the austral summer from December of 1999 to January of 2000. The concentrations of CO2 in surface water of the survey regions would mostly present lower than those in the atmosphere. A significant biological driving force could also been observed in summer waters in both of the above oceans. Air to sea CO2 fluxes were also calculated to compare oceanic uptake capacity of CO2 in both oceans with the world oceans using Liss, Wanninkhof, and Jacobs‘s methods. The averaged CO2 fluxes of air to sea in the western Arctic Ocean or in the MSIZ of the Southern Ocean doubled that in the world oceans.     

The radiative and thermal effects of smoke aerosol over the region of Moscow during the summer fires of 2010

The shortwave radiative forcings of smoke aerosol in the cloudless atmosphere during the summer fires of 2010 in European Russia were quantitatively estimated for the land surface and the atmospheric upper boundary from measurement data obtained at the Zvenigorod Scientific Station of the Obukhov Institute of Atmospheric Physics (OIAP ZSS), Russian Academy of Sciences. Variations in the temperature of the surface air layer due to the smoke-induced attenuation of incoming solar radiation were estimated. The most intensive smoke generation in the atmosphere was observed on August 7–9, 2010, when the maximum aerosol optical thickness amounted to more than 4.0 at a wavelength of 550 nm. In this case, the albedo of single aerosol scattering amounted to ∼0.95–0.96 and the asymmetry factor amounted to ∼0.69–0.70. The maximum shortwave radiative forcing of aerosol amounted to about −360 W/m² for the land surface and almost −150 W/m² for the atmospheric upper boundary. During the period of intensive smoke generation, the cooling of the atmospheric surface layer over daylight hours (12 h) amounted, on average, to ∼6°C. The power character of the dependence of the shortwave radiative forcing of aerosol for the land surface on aerosol optical thickness up to its values exceeding 4.0, which was revealed earlier on the basis of data on aerosol optical thickness (up to 1.5) obtained at the OIAP ZSS during the summer forest and peatbog fires of 2002 in the region of Moscow, was supported.     

Studying of biogenic volatile organic compounds in the atmosphere over Russia

The volatile organic compounds (VOCs) emitted from vegetation into the atmosphere play an important role in atmospheric chemistry and participate in the formation and growth of aerosol particles that affect the atmospheric radiation balance and the earth’s climate. A number of VOCs, such as isoprene, monoterpene, methylvinylketone, and methacrolein, whose surface concentrations were measured between Moscow and Vladivostok in the course of the Transcontinental Observations into the Chemistry of the Atmosphere (TROICA-12) experiment in July–August 2008, are considered. For the first time in Russia, a PTR-MS proton mass-spectrometer was used to measure the VOC concentrations. The continuous series of VOC concentrations in the atmosphere over the Trans-Siberian Railway were obtained, and the characteristic features of their variations were determined. The spatial distribution of the concentrations of biogenic VOC was compared with a map of Russia’s forests. It was found that the maximum concentrations of isoprene between Moscow and Vladivostok correspond to the zones of broad-leaved forests in the Far East and Primorskii Krai, and the maximum concentrations of monoterpene correspond to coniferous forests in Siberia. The obvious correlation between the concentrations of isoprene and the total concentration of methylvinylketone and methacrolein was revealed.     

Environmental changes in the neogene and the biotic response

Among the abiotic factors that determined via the paleoceanographic processes development and evolution of the oceanic biota in the Neogene, noteworthy are the tectonic, volcanic, climatic and extraterrestrial events. The most important tectonic events of such kind include the subsidence of the Faroe-Iceland Threshold 14–13 Ma ago, the closure of the Tethys Ocean in the east 19–12 Ma ago, the orogenesis in the western Mediterranean region and closure of the Mediterranean Sea (Messinian Crisis) 5.59–5.33 Ma ago, the formation of the Central American Isthmus 6.0–3.5 Ma ago, and the opening of the Bering Strait that occurred (according to different data) in the period of 7.4 to 3.1 Ma ago. The most significant climatic consequence resulted from the formation of the Circum-Antarctic Current, the irregular growth of the Antarctic ice shield, the cooling in the Arctic region 3.2–3.1 Ma ago, and the development of continental glaciations in the Northern Hemisphere approximately 2.5 Ma ago. The variations in the atmospheric CO₂ content are correlative with the climatic fluctuations. The entire Cenozoic climatic record reflects the influence of the orbital parameters of the Earth. The Neogene was marked by several significant extraterrestrial events: the fireball falling in southwestern Germany in the middle Miocene 14.8–14.5 Ma ago probably accompanied by enhanced volcanic activity particularly in the rift valley of eastern Africa; the drastically increased influx of interplanetary dust due to the disruption caused by a large asteroid in the late Miocene 8.3 ± 0.5 Ma ago, the fall of a large (>1 km in diameter) asteroid in the Eltanin Fault zone of the Southern Ocean in the terminal Pliocene 2.15 Ma ago; and the explosion of a supernova star, which was probably responsible for the partial extinction of marine organisms at the Pliocene-Pleistocene transition approximately 2 Ma ago.     

Halocarbons associated with Arctic sea ice

Short-lived halocarbons were measured in Arctic sea–ice brine, seawater and air above the Greenland and Norwegian seas (~81°N, 2–5°E) in mid-summer, from a melting ice floe at the edge of the ice pack. In the ice floe, concentrations of C₂H₅I, 2-C₃H₇I and CH₂Br₂ showed significant enhancement in the sea ice brine, of average factors of 1.7, 1.4 and 2.5 times respectively, compared to the water underneath and after normalising to brine volume. Concentrations of mono-iodocarbons in air are the highest ever reported, and our calculations suggest increased fluxes of halocarbons to the atmosphere may result from their sea–ice enhancement. Some halocarbons were also measured in ice of the sub-Arctic in Hudson Bay (~55°N, 77°W) in early spring, ice that was thicker, colder and less porous than the Arctic ice in summer, and in which the halocarbons were concentrated to values over 10 times larger than in the Arctic ice when normalised to brine volume. Concentrations in the Arctic ice were similar to those in Antarctic sea ice that was similarly warm and porous. As climate warms and Arctic sea ice becomes more like that of the Antarctic, our results lead us to expect the production of iodocarbons and so of reactive iodine gases to increase.     

Non-sea-salt sulfate in the marine boundary layer and its possible impact on chloride depletion

1Introduction Sulfurisoneofthemostimportantelements whosebiogeochemicalcyclesarepivotaltotheatmo- sphericenvironmentandtotheclimaticchanges.The predominant,stablechemicalspeciesofsulfurinthe atmosphereissulfuricacidorsulfatewhichunderor- dinaryconditionsexistsmainlyinsmallaerosolparti- cles(Chinetal.,1996;Kerminenetal.,2000;Restadet al.,1998).Sulfuricacidorsulfate-dominatedaerosols areubiquitousintheloweratmosphere.Inthemarine boundarylayer(MBL),non-sea-saltsulfuricacidorsulfate(nss-SO42-)…     

Investigation of the action of hygroscopic particles on a warm convective cloud from the results of numerical simulation

The results of a numerical simulation of the action of hygroscopic particles on a warm convective cloud with the purpose of obtaining additional precipitation are presented. The one-dimensional numerical model considered in this work describes the evolution of the cloud medium in the central part of an axisymmetric convective cloud at the specified height-variable velocity of the upward air flow which forms the cloud. Our model comprehensively describes microphysical processes in the cloud medium with the use of the kinetic equation for the size distribution of cloud droplets. This model makes it possible to obtain the spatiotemporal pattern of the cloud formation and development and to analyze regular features in the cloud evolution under the action of hygroscopic reagents. The cloud characteristics calculated with the use of this model correspond to the cloud parameters observed in natural conditions of the atmosphere. The process of precipitation stimulation by hygroscopic particles in convective clouds with vertical thicknesses of 2.5–4.5 km was analyzed on the basis of the results of numerical calculations. The results of calculations of the dependence of the intensity and total amount of precipitation on the vertical cloud thickness and parameters of particles introduced into the cloud are presented. It is shown that hygroscopic particles with root-mean-cube radii of 1–1.5 μm are the most effective for acting on warm convective clouds with the purpose of obtaining additional precipitation. In this case, the required reagent expenditure is 100–200 kg/km². The conditions necessary for obtaining the maximal positive effect of the action are elucidated.     

Polar marine biology science in Portugal and Spain: Recent advances and future perspectives

Polar marine ecosystems have global ecological and economic importance because of their unique biodiversity and their major role in climate processes and commercial fisheries, among others. Portugal and Spain have been highly active in a wide range of disciplines in marine biology of the Antarctic and the Arctic. The main aim of this paper is to provide a synopsis of some of the results and initiatives undertaken by Portuguese and Spanish polar teams within the field of marine sciences, particularly on benthic and pelagic biodiversity (species diversity and abundance, including microbial, molecular, physiological and chemical mechanisms in polar organisms), conservation and ecology of top predators (particularly penguins, albatrosses and seals), and pollutants and evolution of marine organisms associated with major issues such as climate change, ocean acidification and UV radiation effects. Both countries have focused their polar research more in the Antarctic than in the Arctic. Portugal and Spain should encourage research groups to continue increasing their collaborations with other countries and develop multi-disciplinary research projects, as well as to maintain highly active memberships within major organizations, such as the Scientific Committee for Antarctic Research (SCAR), the International Arctic Science Council (IASC) and the Association of Polar Early Career Scientists (APECS), and in international research projects.     

Reproduction of the large-scale state of water and sea ice in the arctic ocean in 1948–2002: Part I. Numerical model

Calculations were performed using a model of the combined circulation of the Atlantic Ocean (from 20° S), the Arctic Ocean, and the Bering Sea with a resolution of 0.25° by latitude and longitude for 1958–2006. The results are compared with observational data and results obtained by other models. Model estimates were obtained for the evolution of the Atlantic water inflow into the Arctic basin through the Fram Strait and the Barents Sea. Increased transports of Atlantic water inflow into the Arctic basin were found for the first half of the 1990s and 2004–2006. The relation between Atlantic water transports into the Arctic basin and variations in the North Atlantic oscillation is shown. A positive trend of Atlantic water inflow into the Arctic basin through the Fram Strait (0.061 Sv per year) was revealed. The evolution of the freshwater-layer thickness in the Beaufort Circulation (BC) is considered. There are three periods of its increased values combined with the increased anticyclonic vorticity of BC currents: the 1960s, the 1980s, and from 1999 until now. The model estimate for a statistical mean timescale of the cycle of freshwater concentration and sink from the BC is 16 years, which is close to currently existing estimates. The evolution of anticyclonic vorticity of currents leads the variations in the freshwater-layer thickness of the BC by 1.75 years. Since the mid-1970s, there have been long positive trends of both the freshwater-layer thickness and anticyclonic vorticity of currents in the BC. In the same time period, there has been a satellite-registered negative trend in the ice area in the Arctic, which was reproduced by the model.     

Neotectonic dynamics of the marine coastal zone exemplified by the Antarctic Peninsula

The proposed concept of the “marine coastal zone” (MCZ) is substantiated with considering the role of the neotectonics in the formation and evolution of the corresponding morphologic system using the Antarctic Peninsula as an example. For this purpose, the results of the immediate geologic-geomorphologic observations are correlated with an original schematic neotectonic map compiled for the region in question. It is shown that neotectonic movements are responsible for the block structure of the coastal zone representing its most stable element, which is complicated by subsequent regional exogenic coast-forming processes with the glacial one being dominant. Other aspects of the marine coastal zone influenced by neotectonics are also considered. A new (near-polar) type of the marine coastal zone is defined.     

北极和南极表面温度对中低纬度海洋热强迫的响应

利用耦合了平板海洋模型的全球气候模式进行了大量的格林函数实验,以探究两极地区对于施加在中低纬度海域的热强迫的气候响应。结果表明,北极地区的气候不仅受到距离较近的北太平洋与北大西洋的影响,远离北极的热带太平洋以及南太平洋也对其气候有显著的影响,南极地区的气候则主要是受到邻近的南大洋的影响。通过经验正交函数法的进一步分析发现,北极响应最显著的区域包括波弗特海(Beaufort Sea)、拉普捷夫海(Laptev Sea)以及北极中心区附近;南极地区的响应主要集中在别林斯高晋海(Bellinsgauzen Sea)区域。另外,利用温度归因法对辐射反馈过程和大气能量输运分解发现,北极地区表面温度的响应主要是受到了反照率反馈以及垂直递减率反馈的影响,而南极地区的响应则主要是反照率反馈发挥了作用。     

Nanoaerosol formation in the troposphere under the action of cosmic radiation

The level of cosmic radiation has been shown to affect the rate of nanoparticle formation from gas emissions of natural and anthropogenic origins. The acceleration of particle formation processes is mainly caused by the increased concentration of atmospheric ions, which serve as condensation nuclei and thus strongly change the rate of aerosol charging processes. This paper provides a brief overview of the main processes leading to the formation of nanoparticles in the atmosphere. These processes include nucleation, condensational growth, charged particle growth, charging of aerosol particles, and recombination. Particular emphasis has been placed on the role of particle sizes in charging processes. Also, we discuss the influence of aerosol sinks on the rate of aerosol formation.     

北极地区大地构造特征及其构造演化——北极地区大地构造编图研究进展

北极地区具有丰富的油气资源,但是受极度寒冷气候和广泛分布冰盖的影响,北极是全球地质研究程度最低的地区之一。为此,基于最新地球物理数据,结合文献资料中的地貌、地质、矿产资源资料,编制了北极地区大地构造图(1:500万)。通过系统的编图研究,认为北极地区位于泛大陆腹地,中生代以来的构造演化受到冰岛地幔柱的垂向作用和欧亚-劳伦板块缓慢的顺时针旋转的水平作用共同制约。其构造演化可归纳为3个阶段:(1)早中生代:北亚-北美西北部(远东-科迪勒拉)造山带俯冲-造山增生阶段,古太平洋向北俯冲,古亚洲洋最终关闭,泛大陆最终形成;(2)侏罗纪-白垩纪:伴随着加拿大盆地张开,南阿纽伊洋盆俯冲消亡并形成南阿纽伊缝合带,两者之间在运动学上具有耦合联系,并伴随其间转换断层的调节作用;(3)新生代以来北大西洋中脊持续扩展传播,造成欧亚盆地张开和加科尔洋中脊发育。北极地区处于全球不同构造域之间的桥梁和枢纽。随着北冰洋洋盆伸展作用发展及加科尔洋中脊向南传播,它将西南贯通北太平洋构造域(远东造山带),彻底改变全球中生代以来的构造格局。     

Nutrient distributions and new production in polar regions: parallels and contrasts between the Arctic and Antarctic

Polar regions are poorly understood components of global biogeochemical cycles. This paper discusses the influences of nitrate and ammonium concentrations on nitrate uptake (and hence new production), particularly with regard to data collected within marginal ice zones in the Arctic and Antarctic. Subsurface ammonium maxima in waters over 150 m are frequently encountered in the Arctic and occasionally in the Antarctic. Such maxima result from the heterotrophic remineralization of organic matter, and because stratified environments occur more frequently in the Arctic, significant concentrations of ammonium accumulate as a result of lower diffusive losses. Causal agents (bacteria vs. Zooplankton) may also be different in the Arctic from those in the Antarctic. Elevated ammonium concentrations significantly reduce nitrate uptake, and it is suggested that this nutrient interaction may play a significant role in controlling new production, particularly in open water regions. The new production of the Southern Ocean is estimated, and it is suggested that the production and flux from the surface layer is significant relative to the world's oceans.     

Satellite monitoring of trace gas and aerosol emissions during wildfires in Russia

Peculiarities of the formation of carbon gas and fine aerosol emissions into the atmosphere during wildfires are analyzed. A prompt satellite monitoring system and technique for the assessment of burnt areas and volumes of CO₂, CO, and PM_2.5 emissions from wildfires are described. The results of satellite monitoring of the Russian Federation and some Russian regions for different months over 2010–2014 are given; burnt areas and volumes of carbon gas and aerosol emissions throughout the entire territory are assessed. The peculiarities of seasonal frequencies of wildfires and volumes of hazardous gas and fine aerosol emissions in the regions under study are identified.     

Radiative and Thermal Impacts of Smoke Aerosol Longwave Absorption during Fires in the Moscow Region in Summer 2010

The aerosol longwave radiative forcing of the atmosphere and heating rate of the near-surface aerosol layer are estimated for the extreme smoke conditions in the Moscow region in summer 2010. Thermal radiation fluxes in the atmosphere are determined using the integral transmission function and semiempirical aerosol model developed on the basis of standard aerosol models and measurements at the Zvenigorod Scientific Station, Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The aerosol radiative forcing reached 33 W/m² at the lower atmospheric boundary and ranged between–1.0 and 1.0 W/m² at the upper atmospheric boundary. The heating rate of the 10-m atmospheric layer near surface was up to 0.2 K/h during the maximum smoke conditions on August 7–9. The sensitivity of the aerosol longwave radiative forcing to the changes in the aerosol absorption coefficient and aerosol optical thickness are estimated.     

Seasonal variability of the water circulation in the southern ocean and heat, salt, and mass exchange in the Antarctic region and adjacent oceans

The hydrographic fields in the Arctic region are calculated with a three-dimensional nonlinear model of the general circulation in the World Ocean using climatic databases on temperature, salinity, and wind stress. The calculation results show that the seasonal variability of the fields is negligible. The salinity distribution almost does not change from season to season, and slight temperature differences are found only in the upper layer. In the winter period, a moderate intensification of the currents is observed. The formation of an intermediate low-salinity layer is revealed at the Subantarctic front, where the intensive turbulence and transverse circulation in the Antarctic Circumpolar Current near the front result in the sinking of the surface low-salinity waters down to intermediate depths. The low-salinity water propagates in the oceans at intermediate depths northward from the front by advection. The integral values of the seasonal transport of mass, heat, and salt in various sections are presented in tables, and the distributions of appropriate characteristics in these sections are shown in figures. According to the calculations, the highest seasonal variations of heat, salt, and mass exchange in the Antarctic region and adjacent oceans are found in the Atlantic sector.